The Physics Lab

The Laws of Thermodynamics

2008-09-15T04:34:00.000-07:00

There are 3 laws to Thermodynamics -

0 - About thermal equillibrium
1 - About the conservationof energy
2 - About entropy
3 - About absolute zero temperature
Onsager reciprocal relations, sometimes the 4th law of thermodynamics -
About relationships of flows in forces in thermodynamics systems out of equillibrium

Thus these are the 4 laws of thermodynamics... a rather brief topic.

With this, I conclude the chapter on thermodynamics.

Thermal Physics - s.h.c.

2008-07-18T07:06:00.000-07:00

Right... as I said in my last post, I will cover the factors that affect specific heat capacity and the symbols in specific heat capacity.

The Factors that Affect Specific Heat Capacity.

They are namely: degree of freedom, Molar mass, Hydrogen bonds and Impurities.

1. The degrees of freedom

The degree of freedom actually refers to the amount of space an atom has to move in a molecule. As the space an atom has in a molecule increases, the amount of kinetic energy posessed by the molecule increases, thus it is an undeniable fact that the thermal energy a substance posesses increases as the degree of freedom increases. As the thermal energy of a substance increases, its specific heat capacity will definitely decrease.

2. Molar mass

er... pretty obvious... right? As the mass of a substance increases, diffrent values for specific heat capacity will arise, as diffrent masses used to measure c will give rise to diffrent values, because of the rounding errors and the accuracy when the thermometer measures the temperature of the substance. Thus it is always advisable to use quantities that are easily convertible to the standard kilogram with minimal, or even zero discrepancy (e.g. 100g).

3. Hydrogen bonds

There are powerful intermolecular bonds between the molecules in a substance, thus providing another place where kinetic energy is stashed up.

4. Impurities

Impurities will affect virtually anything... I think that this is the only explanation i will give regarding this part.

Symbols Used in Specific Heat Capacity

Water (liquid): c-p = 4.1855 J g–1 K–1 (15 °C), and…
Water (liquid): C-vH = 74.539 J mol–1 K–1 (25 °C)

not really of any help, but anyway, c stands for specific heat capacity.

This is all I have to say for today. Thank You.

Thermal Physics - s.h.c

2008-07-12T07:37:00.000-07:00

In the next few posts, i will try to understand what thermal physics is. The diffrent aspects of thermal physics shall be covered.

As for this particular post, the topic I will be covering is the specifc heat capacities of substances. The specific heat capacity is the amount of energy in joules requred to rase the tempereture of a kilogram mass of a substance by 1 Kelvin.

c = xJ/kgK

where: c is the specific heat capacity,
x is the number of joules (amt. of energy)

e.g. the specific heat capacity of water is 4200J, therefore it is represented as:

c(water) = 4200J/kgK

enough said about formulae. Now, how exactly do we determine the specific heat capacity of a substance? In this experiment, i will attempt to find the specific heat capacity of copper.

The apparatus needed are: 1 calorimeter, 1 100g mass of copper, 1 balance scale, ice, 1 thermometer, 1 bunsen burner, 1 glass rod, string.

1. Half fill the calorimeter with water, record the temperature as T(1).
2. Weigh the mass of the calorimeter, record the mass as M(1).
3. Put the current apparatus aside. Prepare a boiling beaker of water on a flame.
4. Attach the copper mass on the glass rod using the string.
5. Immerse the copper mass into the boiling water for 2 minutes
6. Record temperature of boiling water while copper mass is inside, record as T(2).
7. Take the copper mass out and put it in the calorimeter.
8. Measure the temperature of the copper mass, NOT THE WATER!
9. When the temperature of the copper mass has reached thermal equillibrium with the water, measure the diffrence in temperature of: 1) the room temperature water and water
after thermal equillibrium. 2) boiling water and copper mass after thermal equillibrium.
10. The s.h.c of water is 4200J/kgK. use this to calculate how much energy was gained by the water.
11. Using energy lost = energy gained, we can tell how much energy the copper mass lost.
12. Take the amount of energy lost by the copper mass and divide it by the change in the copper mass' temperature, that value is the s.h.c of copper in the form xJ/(100g)(K).
13. Take the value and multiply it by ten, then you will obtain the s.h.c of copper in the form xJ/kgK

We can use this method to find the s.h.c of many diffrent substances, so please, go and try it out!

How is specific heat capacity so far? This is only the beginning, next time I post, I shall cover the factors that affect scecific heat capacity and the symbols used in the calculation of specific heat capacity.

That is all I have for today. Thank You.

The Bermuda Trangle

2008-07-10T05:17:00.000-07:00

In this post, I shall talk about the question that still remains a mystery- why do people go missing inthe Bermuda Triangle?

Gravitational fields are very strong in the Bermuda Tringle. When gravitational fields are very strong, the linearity of time is distorted, hence time will move very slowly with respect to the normal passage of time on earth ( i.e. 1s/s).

Consider a body moving at a velocity of 10ms^-1. In normal time, v would be at a value of 10ms^-1. However, in the bermuda triangle, the gravity is very strong, thus time moves very slowly. The same moving body at a velocity of 10ms^-1 in normal linear time is now moving in the bermuda triangle where the gravity is very strong. What would happen?

In the bermuda triangle, the time is moving at a fraction of the normal earth time (the exact gravitational time dilation can be measured by the Einstein Field Equations). Therefore, instead of moving at 10ms^-1 , the body is now moving 10m in a fraction of a second, because of time dilation. Therefore when the speed is amplified, the air resistance increases, therefore is it right to deduce that the air resistance produced by the speed is enough to burn the body, as ships and planes are moving at an incredible speed.

This is all I have to say today, please leave some comments. Thank You.

My first post - the nature of time

2008-07-05T23:29:00.000-07:00

As you can see, this is what this blog is about... so if you are interested in physics, just feel free to read this blog.

In this blog, i shall talk about things of my interest, mainly in the field of theoretical physics and perhaps a little philosophy.

In this first post, i shall discuss about the nature of time. As you know, time has a linear form unless in 'special conditions', most of the time, black holes. In its linear form, time progresses normally, (i.e. 1s/s). However, if there is a black hole in the passage of time, time will slow down. When time slows down because of gravitational time dilation, time will slow down, but will the rate at which the person who is experiencing the time dilation and an observer observes the motion of things be affected? Even if the motion of things is affected, by what and are there any other special circumstances in which they will be affected, and in the abscence of these special circumstances, what will happen? These are the questions that would be tackled in the branch of Theoretical Physics.

In the prescence of a black hole, the gravity affects the linearity of time itself. Therefore, there is gravitational time dilation. But, is it possible to calculate in exact quantities the magnitude of gravitational time dilation? It is a very complicating process which involves the use of the constant factors in universal time, but with these black holes appearing and disappearing in a split second, is it really possible to derive any constant regarding time that is not affected or totally negates and cancels the effcts these black holes create (e.g. gravitational time dilation)?
These are questions that I am currently pondering about. If you have any suggestions, I welcome you to post a comment here , but no spams please...

That is all I have to say for now. Thank You for your time =)